Retain declared path ordering in OpenAPI YAML output. (#6680)

* Add pyyaml.dump(..., sort_keys=False) to not sort openapi keys alphabetically
* Retain ordering of paths as provided in urlconf in OpenAPI schemas.

docs/community/release-notes.md

@@ -44,6 +44,7 @@ You can determine your currently installed version using `pip show`:
 
 **Date**: [Unreleased][3.10.0-milestone]
 
+* Updated PyYaml dependency for OpenAPI schema generation to `pyyaml>=5.1` [#6680][gh6680]
 * Resolve DeprecationWarning with markdown. [#6317][gh6317]
 * Add `generateschema --generator_class` CLI option
 
@@ -2138,4 +2139,5 @@ For older release notes, [please see the version 2.x documentation][old-release-
 [gh6613]: https://github.com/encode/django-rest-framework/issues/6613
 
 <!-- 3.10.0 -->
+[gh6680]: https://github.com/encode/django-rest-framework/issues/6680
 [gh6317]: https://github.com/encode/django-rest-framework/issues/6317

requirements/requirements-optionals.txt

@@ -6,4 +6,4 @@ django-guardian==1.5.0
 django-filter>=2.1.0, <2.2
 coreapi==2.3.1
 coreschema==0.0.4
-pyyaml
+pyyaml>=5.1

rest_framework/renderers.py

@@ -1049,7 +1049,7 @@ class OpenAPIRenderer(BaseRenderer):
         assert yaml, 'Using OpenAPIRenderer, but `pyyaml` is not installed.'
 
     def render(self, data, media_type=None, renderer_context=None):
-        return yaml.dump(data, default_flow_style=False).encode('utf-8')
+        return yaml.dump(data, default_flow_style=False, sort_keys=False).encode('utf-8')
 
 
 class JSONOpenAPIRenderer(BaseRenderer):

rest_framework/schemas/generators.py

@@ -54,7 +54,7 @@ def endpoint_ordering(endpoint):
         'PATCH': 3,
         'DELETE': 4
     }.get(method, 5)
-    return (path, method_priority)
+    return (method_priority,)
 
 
 _PATH_PARAMETER_COMPONENT_RE = re.compile(